Im 15 and I tryed creast white strips, that are suppose to whiten your teeth. and as the instructions said, to leave them on for 30 minutes, i did. when i took them off, the stained all white patches all over my teeth, and its VERY notice able, i ruined my teeth really badly. . does anyone have tips on how to get my teeth one colour? it looks real bad, and schools starting in 3 weeks, should I consult a dentist?